PRODUCTION PROCESS OF PIPE FITTING

Pipe fittings are the general name of the parts and components that play the roles of connection, control, direction change, diversion, sealing and support in the pipeline system. According to the different processing technology, it can be divided into four categories: butt welded pipe fittings, socket welded pipe fittings, threaded pipe fittings and flanged pipe fittings. Today, we are going to know about the production flow of pipe fitting.

 

1. Heating

For pipe fittings manufactured by hot forming, to meet the requirements of material deformation in forming process, it is necessary to heat the billet during forming. Heating temperature is usually determined according to material and process requirements.

When forming a hot push elbow or a hot bend pipe, the method of medium or high frequency induction heating is usually used, and the method of flame heating is also used. This heating method is continuous and synchronous heating with elbow forming process. The billet is heated in motion and the forming process is completed.

When hot-pressing elbows, hot-pressing tees or forgings are formed, the methods of reverberatory furnace heating, flame heating, induction heating or electric furnace heating are usually used. This kind of heating is to first heat the billet to the required temperature, then put it into the die to press or forge.

 

2. Welding

Pipe fittings with weld include two cases. One is pipe fittings made of welded pipe. For the pipe fittings factory, the forming process of welded pipe is basically the same as that of seamless tube forming. The forming process does not include welding procedure. And the other is the welding procedure needed by pipe fitting manufacturer to complete tube forming. The elbow formed by assembling and welding after monolithic pressing and the tee formed by welding into tube blank after steel plate drum and then pressing are typical examples.

The welding methods of pipe fittings include manual arc welding, gas shielded arc welding and automatic welding. The manufacturer should compile welding procedure rules to guide the welding work, and conduct welding procedure assessment according to the corresponding specifications. That is to verify the correctness of the welding procedure rules and assess the welding ability of the welding construction. Welders engaged in pipe welding should pass the examination of the quality and technical supervision department and obtain the corresponding qualification certificate before they can engage in the welding of related steel grades.

 

3. Heat Treatment

Heat treatment process is an important part of pipe manufacturing. By means of heat treatment steps of heating, heat preservation and cooling, the work hardening, residual stress and metal deformation defects produced during the forming process are eliminated. So the metal structure and properties of the pipe fitting after forming are changed, which will restore to the state before deformation processing or improve their properties.

 

In short, pipe fittings, whether the cast fittings or the forged fittings, have to undergo the process of heating, welding and heat treatment so that they can obtain good performance.